Excavation near the tree will possibly kill it if you're too close (unless of course it's an above-ground pool in which case it still might suffer with the squished soil over its root system).

I do have an orange tree about 4 feet from my pool. I suspect the pool and tree were planted at about the same time (early 1960s). It's lovely. On a hot day you can sit on the steps and enjoy the shade. Not much smells nicer than citrus blossoms.

I didn't think there was anything messier than a jacaranda until I got this tree, but half the year we're fishing out oranges and the other half, flower petals. It's awful or wonderful depending on if you're cleaning or relaxing.

So I don't know how the root situation will work for you (try the tree forums here on GW perhaps to see what your oak can take) but instead of getting the pool close to the tree, it might be better to try to keep them at a good distance and have a deck or something between the two.

I'm currently working on design of a pool near a tree which the municipality will not allow to be removed. An arborist has been brought in and will not allow any excavation or concrete structure to be build within 10 feet of the tree trunk in this case but every situation varies. Different types of trees have different root structures and therefore requirements. In this case, due to finished elevations etc, we have worked out a design to allow the pool to be within 5' of the tree without risking anything.

Every night, as I skim and scoop, I curse the homeowner that planted a pear tree 8 feet from our pool. :) We are big tree lovers, so when my Florida cousin said "you will come to hate trees when you have a pool" I poo-poo'd her. Now, I know she was right. The Texas Live Oak is also nearby, and drops acorns and leaves all over the pool, too. I still love trees, but only in my front yard (and even that is a pain, a huge oak tree whose leaves somehow all manage to blow over our two story house and into the pool). We've stationed greet pop-up trashcans near the pool area, because anything scooped/skimmed just blows right back in if it isn't contained.

After 6 years of trying to save the trees by our pool we chopped them down. Best thing I ever did. Not only for the cleanup aspect, but the roots where starting to go towards the pool deck. The roots had already ripped up our paver patio. We have smaller trees and our neighbors tress that do give us shade. Although we still battle stuff from honey locusts and maple trees.

I would get advise from an arborist about the tree roots. You do not want to build too close to the tree.

No real tips or suggestions, but these pictures might interest you:

yes...but let's see it in 5 years